The Lancet has published an article suggesting that the first cases of BSE were caused because cattle were given manufactured feed that contained human remains from sufferers of one of the standard variations of CJD.
It is known that during the revelant period, feed was made from bone and associated material. This was to increase the protein content and thereby get the cows to give more milk. A source of these bones was the Indian sub-continent where collecting them from fields and rivers is a local industry. The suggestion is that the incomplete cremation and deposition of the unburned body of someone already infected with a prion disease meant their bones were collected as part of the trade.
More details below the fold.
The theory is controversial but does seek to explain how the original infection of cattle occurred. It has not been dismissed out of hand and certainly bears investigatin as the authors point out.
More details from the BBC article
Hindu funerary practices require that human remains are disposed of in a river, preferably the Ganges. Although the body should ideally be burned, many people cannot afford enough wood for a full cremation, the report's authors claim.
Simply smoking the pelvis in women and the torso in men is sometimes enough. And many complete corpses are thrown into the Ganges.
"There are a whole range of public health concerns over Ganges pollution," lead author Professor Alan Colchester told the BBC News website.
"But amongst all the recognition of potential problems, I don't think anyone has thought about the very rare but very important risk posed by the corpse of someone who has died from a version of CJD."
Human remains have been described in material delivered to processing mills. And during the 1960s, human material was confirmed in consignments of bones shipped into French docks from Asia.
The later spread caused probably by feeding cattle infected cows and sheep was bad enough. Now we find that it may have been started by feeding humans to cattle!